Flashing lenses illuminate the way at a museum of lighthouse artifacts

ROCKLAND, Maine -- In the early 1800s, a Frenchman named Augustin Fresnel discovered that by breaking the solid piece of glass surrounding a lighthouse beam into pieces called prisms he could control the light's direction and greatly increase its range. Fresnel (freh-NELL) lenses became the standard for lighthouse illumination, and the ornate, multifaceted glass sculptures are as beautiful to look at today as they were to spy from a ship at sea more than 150 years ago.

When you enter the Maine Lighthouse Museum, you may be temporarily blinded by the flash from a rotating Fresnel lens of the fourth order that once lighted the way into Boothbay Harbor, or by the beam from a third-order lens from Maine's Matinicus Rock light, about 20 miles off the entrance to Penobscot Bay. (Fresnel lenses range from sixth order, at about a foot, used for harbor lighting, to first order, standing 10 feet high with some 300 prisms, used along the coast.) But as you move through the museum, you become accustomed to, even soothed by, the pulsating lights that seem to mimic the rhythm of the sea.

This summer marked the opening of the new home of the collection formerly housed at the Shore Village Museum, which closed last October. The museum claims the largest collection of lighthouse lenses in the United States, assembled for the most part by retired Coast Guard officer Ken Black, who oversaw the local Coast Guard station in Rockland in the 1970s and literally intercepted many of the items as they were on their way to the dump, according to Ted Panayotoff, the museum's volunteer coordinator.

The museum is very much a work in progress, said Panayotoff, with perhaps only 30 percent of the collection on display. Over the winter, the museum will expand into an additional 5,000 square feet. Many more lenses are in storage, and by spring the museum expects to have a second-order lens installed.

Visitors learn there are four types of light-driven navigational aids: lighthouses, lightships, beacons, and lighted buoys. A timeline points out that two of the seven wonders of the ancient world were lighthouses: Pharos of Alexandria, Egypt, and the Colossus of Rhodes in Greece. If it were still standing, Pharos, at 450 feet, would be the tallest lighthouse in the world.

The first lighthouse in the United States was built in Boston Harbor in 1716. In Maine, the number of active lighthouses peaked at 67 when the last one opened in 1910. Today, 63 are left, of which 26 are open to the public.

Memorabilia from the heyday of the US Light House Service, the federal agency once charged with maintaining all the lighthouses in the country, convey the importance and prestige attached to the corps: fine china engraved with USLHS, a silver serving tray, a keeper's insignia embroidered with a ''K" and hash marks to indicate length of service. (In 1939, the Light House Service merged with the US Coast Guard, which now maintains the lighthouses.) There's an extensive display on lifesaving, including ingenious contraptions using ropes and pulleys and a tally board with instructions to survivors of shipwrecks, carved in English, Spanish, and French. Another display shows foghorns and bells.

Be sure to step out onto the observation deck and take in the view of Rockland Harbor and the Rockland Breakwater Lighthouse, which was illuminated by a fourth-order Fresnel lens from 1902 until it was automated in 1965.